XL ChIP-seq: For ARID2, SS18, BRG1, TEAD4, FOSL2, CTCF, and MITF cells were cross-linked with 2 mM disuccinimidyl glutarate (DSG, Pierce 20593) in PBS for 45 min followed by 1% FA for 10 min at RT. For H3K27ac and H3K27me3 cells were cross-linked with 1% FA for 10 min at RT. ChIP was performed as previously described (Fontanals-Cirera B, Hasson D, Vardabasso C, Di Micco R et al. Harnessing BET Inhibitor Sensitivity Reveals AMIGO2 as a Melanoma Survival Gene. Mol Cell 2017 Nov 16;68(4):731-744.e9) ChIP-seq: Libraries for ChIP-seq were done as previously described (Fontanals-Cirera B, Hasson D, Vardabasso C, Di Micco R et al. Harnessing BET Inhibitor Sensitivity Reveals AMIGO2 as a Melanoma Survival Gene. Mol Cell 2017 Nov 16;68(4):731-744.e9) ATAC-seq: For all ATAC-seq libraries, 50k cells were harvested, tagmented with 2.5-5uL Nextera Tn5 Transposes from nextera for 30 min, amplified up to 10 cycles and purified essentially as previously described in ATAC protocols. Purified libraries were then size selected on 2% agarose gel (150-700bp).